2. Academic Validation
  3. Development of an ultrasensitive sandwich immunoassay for detecting small molecule semicarbazide

Development of an ultrasensitive sandwich immunoassay for detecting small molecule semicarbazide

  • Food Chem. 2023 Dec 15:429:136835. doi: 10.1016/j.foodchem.2023.136835.
Shiwei Zhang 1,  Ronghu Feng 1,  Huiling Wu 1,  Jiping Guo 1,  Yingchun Zhou 1,  Xintian Lai 1,  Yanyan Sun 2,  Yudong Shen 3,  Bing Liu 4,  Xingxing Yang 5,  Bingzhi Wang 5
Affiliations

Affiliations

  • 1 Shenzhen Academy of Metrology and Quality Inspection, Shenzhen, PR China.
  • 2 Department of Anesthesiology, Shenzhen University General Hospital, Shenzhen University, Shenzhen, PR China. Electronic address: yysun@szu.edu.cn.
  • 3 Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, PR China. Electronic address: shenyudong@scau.edu.cn.
  • 4 College of Material Science and Engineering, Guangdong Research Center for Interfacial Engineering of Functional Materials, State Key Laboratory of Fine Chemicals, Shenzhen University, Shenzhen, PR China.
  • 5 Shenzhen Bioeasy Biotechnology Co., Ltd., Shenzhen, PR China.
PMID: 37463535 DOI: 10.1016/j.foodchem.2023.136835
Abstract

Ultrasensitive sandwich immunoassays for detecting the small molecule semicarbazide (SEM) were developed based on derivatization. Several SEM derivatizing agents were synthesized by linking o-nitrobenzaldehyde (NBA) and biotin with dihydroxyalkanes (different lengths), which were then used to evaluate the distance effect of two epitopes. Sandwich ELISA for SEM derivatives was developed using an anti-SEM-NBA antibody and horseradish peroxidase-labeled avidin or anti-biotin antibody as a secondary conjugate. The advantageous distances of the two epitopes under the double-antibody sandwich and antibody-avidin sandwich modes were ≥12 and ≥13 Å, respectively. Under the distances, the sensitivities of the sandwich ELISA were no lower than those of competitive ELISA. The obtained optimal EC50 values were 11.2 pg/mL (double-antibody sandwich with the epitope distance ≥16 Å) and 7.3 pg/mL (antibody-avidin sandwich with the epitope distance ≥17 Å). Compared with competitive ELISA, the developed method achieved a 30-fold improvement in sensitivity, with simpler aquatic product pretreatment.

Keywords

Epitope distance; Sandwich immunoassay; Semicarbazide; Small molecule.

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